Just did a GCL test in OpenFOAM 2.1.1, and found that the ALE implementation in OF fails to conserve a uniform solution field. The attached pictures show my result. As can be seen, after some deformation, the originally uniform velocity field got distorted and no longer uniform and has none zero vertical component, which is not right. Refine the mesh will only make the situation worse! Has anyone here studied this before? It's been confirmed that this violation of GCL can introduce accuracy as well as stability problems in ALE solvers. Any comments please?